1. Field of the Invention
The present invention relates generally to lighting systems and, more particularly, is concerned with a freestanding luminaire having a floor-supported frame adapted to be placed at a side of a work station in an open plan office and which is integrated with a plurality of lamps and a light enclosure so as to form a light fixture supported in cantilevered fashion over the work station.
2. Background of the Prior Art
Many modern offices and workplaces employ lighting systems which do much more than provide adequate illumination. They provide adequate illumination with the least possible consumption of energy. For a lighting system to be economical it must maximize the use of the most efficient lamps installed in luminaires capable of confortably, effectively, and with good appearance directing a high percent of the lamp light to the points or area where it is needed. Further, the lighting system must be able to do this with very little maintenance cost. In some systems the maintenance cost of cleaning luminaires and replacing worn-out lamps is excessive. The problem of selecting and designing a lighting system that will effectively meet all of these requirements is a difficult problem.
Heretofore, lighting systems have used an endless variety of patterns for arranging lighting fixtures in a room. In selection and design of a lighting system, the location of the luminaire, or location of the people in the room relative to the luminaire, is exceedingly important in establishing satisfactory conditions of visual comfort and in minimizing ceiling reflections.
Recent lighting system designs, especially in open plan offices, have been quite effective in employing the so-called task-ambient principle, in which a fairly low level of general illumination is provided from the ceiling with localized task lighting being provided at the specific location where the task is being performed. Task-ambient lighting can result in very good visibility with low power consumption. In a drafting room, for example, the task lighting may consist of fluorescent or incandescent fixtures mounted on drafting boards, or on chains suspended a few feet above board level.
Many different luminaires appear in the prior art for providing localized task lighting. Representative of the prior art are the luminaires disclosed in U.S. Pat. Nos. to Jarrett et al (2,553,094), Neumann (3,341,702), Horan (3,356,841), Thornton (3,535,509), Shemitz (4,173,034), Wakamatsu (4,300,185) and Sato et al (4,388,676); in Japanese Pat. No. 54-155678; and in a brochure by Keene Lighting Products advertising the Deskmaster lighting system.
While many of these luminaires of the prior art would appear to operate reasonably well and generally achieve their objectives under the range of operating conditions for which they were designed, a need still exists for a fresh approach to luminaire design for task-ambient lighting in the open plan office. Such approach should make installation of the luminaire easier, maximize visual comfort for users, improve its structural integrity and provide more flexibility in its use while minimizing the cost of cleaning and maintaining it.